Republican Senate Minority Leader Mitch McConnell said he would like to increase the amount of troops left in Afghanistan after the 2014 withdrawal. (Photo credit KAREN BLEIER/AFP/Getty Images)

WASHINGTON (AP) — The United States should keep a residual force of about 10,000 in Afghanistan after combat forces leave at the end of 2014, the Senate Republican leader said Monday after a series of meeting with military leaders in the country.

Sen. Mitch McConnell, who led a congressional delegation to Afghanistan and Israel, expressed optimism about an 11-year war that now stands as the longest in American history, and the prospect of Afghans assuming a lead role in the fighting.

“My observation about Afghanistan at this point is this is the first time I’ve left there with a sense of optimism,” he told reporters in a conference call. “I think there’s a widely held view among the American military leaders there — we met with Gen. (John) Allen — that this has a very great potential for a happy ending after 2014, provided we have a residual force that we can provide for training.”

The United States now has 66,000 troops in Afghanistan. The U.S. and its NATO allies agreed in November 2010 that they would withdraw all their combat troops by the end of 2014, but they haven’t decided on the scope of future missions to contain al-Qaida and the size of a remaining force.

Obama administration officials gave the first clear signal last week that it might leave no troops in the country after December 2014. Administration officials in recent days have said they are considering a range of options for a residual U.S. troop presence of as few as 3,000 and as many as 15,000, with the number linked to a specific set of military-related missions like hunting down terrorists.

Defense Secretary Leon Panetta is believed to favor an option that would keep about 9,000 troops in the country.

McConnell said the military leaders were somewhat cautious about pushing for a specific number as the decision will be made by the White House. The Kentucky lawmaker, who made his seventh trip to Afghanistan, did make his own recommendation.

“I think we’re going to need a minimum of about 10,000 troops to provide adequate training and counterterrorism in the post-2014 period and we anticipate there will be forces from other countries that will remain here beyond 2014 as well,” McConnell said.

The number from the Senate GOP leader could influence other members of Congress as they weigh the continued American presence in Afghanistan amid increasing war-weariness from constituents.

A sticking point for President Barack Obama and Afghan President Hamid Karzai, who met last week, is whether any U.S. troops remaining after 2014 would be granted immunity from prosecution under Afghan law. Immunity is a U.S. demand that the Afghans have resisted, saying they want assurances on other things — like authority over detainees — first.

“There is a widely held view that the Afghan army is definitely coming up to speed,” McConnell said at a stop in Aviano, Italy. “I’m optimistic that this country will be able to maintain itself after we’re largely gone.”

In a separate appearance, Afghan ambassador to Washington H.E. Eklil Hakimi said under security negotiations to flesh out what the two presidents decided last week, U.S. special operations troops could stay at their posts in the villages, with Afghan special operations forces leading the program to train local militiamen to fight the Taliban.

“Afghans will be in in the lead,” he said.

His remarks to reporters Monday clarified Karzai’s remarks Friday when he stated all foreign forces would leave Afghan villages in the spring.

Hakimi also predicted progress on reconciliation talks with the Taliban, aided by another release of Taliban prisoners by Pakistan. But this time, Afghan officials have asked Pakistan to let them know when, where and whom is being released.

“We are in talks to make sure to have a proper monitoring mechanism, and they should notify us and do things in a systematic manner,” Hakimi said.

McConnell was joined on the congressional trip by four Republican senators — John Barrasso of Wyoming, Jeff Flake of Arizona, Ted Cruz of Texas and Deb Fischer of Nebraska. Flake, Cruz and Fischer were just sworn in a week ago.

In Israel, they met with Prime Minister Benjamin Netanyahu. McConnell said the threat from Iran tops Israel’s list of concerns.